The present invention relates to nipples or risers for coupling a sprinkler head to a sprinkler system pipeline and, more particularly, to a single piece nipple which bends when an excessive deflecting force is applied to the sprinkler head or nipple from any direction and returns to an upright position as the deflecting force is removed.
Nipples or risers are utilized in many residential and commercial sprinkling systems to connect sprinkler heads to metal or plastic pipelines. A riser is typically coupled to a connector fitting in the pipeline such as a T-joint. Both the riser and the T-joint are susceptible to damage from the sprinkler head's exposure due to inadvertant contact by people, lawn equipment, vehicles, and the like. Sprinkler systems have been plagued with costly repairs and replacement from broken or leaking risers and joints which were too rigid to withstand day-to-day punishment. In addition, a person who inadvertantly strikes or makes contact with a rigid riser may himself be injured. Further deterioration of a riser may result from extremely low temperatures and corrosion due to the prevailing weather conditions.
Newer risers have avoided some of the problems of rigidity by having a pipe or center section made from flexible material such as rubber with rigid threading or PVC pipe fittings connected at both ends thereof. Other risers have overcome this rigidity problem by providing a helical or coil spring to interact with a flexible, but not resilient, pipe, thereby enabling the pipe to return to an upright position. However, such springs are normally made of metal susceptible to deforming from contact with excessive deflective forces. When a spring becomes deformed, it must be replaced because the riser will no longer return to its proper, upright position. The springs may also break or oxidize under various weather conditions.
None of the previously mentioned risers have eliminated the inherent problem that their end portions and/or the correspondingly mated connector fittings of the sprinkler head or pipeline may still rupture from a heavy force transmitted into the fitting connection. In addition, a deflective force may strip or pull out the threaded end portion.
The replacement of risers or T-joints normally results in the area surrounding the sprinkler head being dug up. In addition, the removal of the broken riser or nipple can be difficult depending upon the state of the deteriorated riser.